New Vegas DLC

To preface, every DLC ups the level cap by five, and adds new perks to the core game.


Dead Money

Influenced by Dead Space, this is a survival horror variant, and enemies only die if dismembered.  As far as survival horror, they nailed it.  You take nothing with you to this area, so no ammo, armor, or your favorite weapons.  You're constantly low/out of ammo, health points, and items.  They also tried (inevitably failing) to make a creepy area.
This would have satisfied me.  I mean, not pissed me off as much as New Vegas.  But then they added a toxic cloud to areas, and decided that radios are proximity mines.  Yay! 
Fifth-ass (much less than half-ass) programming kept me from finishing this tedious, hard, pointless DLC.  Not that I should be surprised; alternate game-breaking glitches are also included. 


Honest Hearts

After Dead Money, Obsidian made another forgettable expansion.  A previous general of The Bad Guys is helping savages fight other savages.  This is less glitchy, but again, rather unsatisfying.  This DLC was better than the original game because they had those plants (used to make things with the Survival skill) all over the place.  It was cool to be able to really get some use out of the Survival skill.


Old World Blues

This was surprisingly awesome, and if it was a standalone game I'd tell you to play it right now.  We still have problems with the engine, but... I have no idea how this was made by the same development team.  Instead of a world of psychos and assholes, you're in a world of ridiculous, hilarious machines.  This is not only the best DLC, but far more fun than the core game itself.  Unlike the other DLCs, you get some useful perks and powerful weapons from playing.  So, there's a reason to play this one, AND it's a lot of fun.

Additionally, you'll get the best house in the game.  A house with a reloading bench, storage, a bed, and a workbench to start.  With upgrades, your home includes a free doctor, a store that can repair your gear, a garden area for every plant available, and multiple ways to convert things into other things (useful for making items).  Your house's appliances have personalities, further giving the game humor and character that was completely lacking before.  My only wish was that this DLC had as much to do (or more) than the rest of the game.  If you have New Vegas, get this one and forget the others.


Lonesome Road

...is not out yet!  But when it comes out, if I play it, I'll edit this post.